1. Field of the Invention
The invention relates to an adjustable support assembly for a prior art seating device, such as a stool or chair. More particularly, this invention relates to an adjustable support assembly adapted to support the feet of a user of the seating device in an ergonomically correct position. The support assembly may be adjusted toward or away from the post of the seating device, so the support assembly may be utilized with a variety of standard sizes of seating devices. Further, the legs of the support assembly may be positioned on the support to selectively lock the support to prevent rotation of the support with respect to the chair.
2. Description of the Related Art
In the workplace, persons are often required to perform repetitive manual tasks in a sedentary position. By maintaining a sedentary position throughout the workday, the person can become fatigued without proper support. Remaining in that sedentary position may reduce blood flow through the legs as well. Utilizing ergonomic principles when designing furniture may increase worker productivity, decrease worker fatigue and absenteeism, and improve blood flow throughout the body.
A stool differs from an industrial chair in the workplace. A stool is designed to support a user, such that the user's feet do not touch the floor. A chair, on the other hand, is adapted to support a user such that his or her feet at least partially contact the floor. As such, stools may be utilized in situations that have a higher working area than do chairs.
Standard height workstations for seated tasks are typically at or below 30″ to the top surface. Traditional industrial stools for users in the laboratory and manufacturing environment are generally designed to elevate a worker to a non-standard height workstation. As workstation height and therefore working height is increased, the surface of the seating device must be raised to a level where foot contact with the floor is no longer possible for most of the population. This range of seating is generally classified as “stools,” as opposed to industrial chairs, etc.
Prior art stools, chairs, and other seating devices typically are comprised of a plurality of legs, generally five, dispersed in wagon-wheel fashion in a substantially-horizontal plane. A castor is typically provided at the end of each leg, which allows the stool to be moved relatively easily. In the center of the legs is located a post, having a neck toward the top of the post. A seat is located atop the post. Generally, the seat is adjustable on the post such that the height of the seat may be adjusted. Thus, the same stool may be used by more than one user, or for use by the same user various working levels.
In some prior art stools, the user's feet are not supported at all. Thus, the circulation through the legs of the user is hampered. This configuration is less than ideal, the circulation being minimized in the user's legs.
In other prior art stools, it is known to provide a support foot ring (generally comprised of metal, such as chrome) to support the user's feet. In some systems, the standard foot ring surfaces are chrome hoops of steel tubing. These hoops provide little traction due the low coefficient of friction of chrome surfaces. Stools or other seating devices may be equipped with foot rings attached to the lift-cylinder column or center post of the stool. These foot rings are typically capable of being locked at various heights (as indicated by the type of work being performed by the user) by hand tightening a friction clamp via a knob located near the center of the foot ring and adjacent to the lift column.
However, the extent the clamp secures the footrest at a given height on the post of the stool, chair, or seating device is dependent on the strength of the user tightening the clamp. Additionally, over time, these clamps may tend to wear and therefore may fail to maintain the desired height.
Several attempts to design footrests that clamp better have been made in the past. For example, some prior art systems include a base with certain fixed-height elements, such as legs, around the perimeter of the base. These bases or pedestals generally are not adjustable and are relatively permanently affixed to the chairs. Thus, the user must select the proper stool, chair, or other seating device with the proper pedestal for a given task closest to that for the desired work height. This approach may prove costly because of the materials needed to provide sufficient support for the user's feet forces seen in normal use. Further, these systems lack the adjustability, so multiple chairs are needed if all users are to be in ergonomically-correct orientations during work.
Also, prior art supports generally are not designed to rotate about the post of the stool. It would be desirable to provide a foot support capable of rotation around the base about the post. It would be desirable to have various platforms of different heights in stair-stepping fashion.
Further efforts to increase the use of prior art foot rings include increasing the diameter of the foot ring. However, if the diameter of the foot ring is increased excessively, then when a user applies weight to the foot ring when exiting the seating device, the entire seating device may tend to tilt or tip over. Thus, a need exists to provide an adjustable assembly for a seating device that is less likely to cause the seating device to become unstable and/or tilt than prior art attempts.
Further, there exists a need for an apparatus that may serve as a retrofit kit for existing stools in the field that would maintain the desirable features of providing a support at multiple heights. Such an apparatus would be preferably manufacturable at low cost. Further, it is desirable that such an apparatus could be assembled to existing stools, chairs, or other seating devices with no tools required, and with no disassembly of the stool, chair, or seating device required (e.g. removal of the seat to install the apparatus). Further, the apparatus should be versatile such that the apparatus is adapted to accommodate many prior art stool, chair, or other seating device configurations currently in use.